<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
</html>
<script>

  /*
    两个方法，window是可以被省略的。

   window.setTimeOut()   


    window.setInterVal()
  */

</script>